Time to positivity of a rapid bedside assay for cardiac-specific troponin T predicts prognosis in acute coronary syndromes: a Thrombolysis in Myocardial Infarction (TIMI) 11A substudy.
OBJECTIVE
We sought to determine whether the rapid bedside assay for troponin T identified patients at risk for a more complicated hospital stay and a higher rate of adverse clinical events.


BACKGROUND
In patients with an acute coronary syndrome, the amount of cardiac-specific troponin T released bears a stoichiometric relation to the extent of myocardial damage.


METHODS
In 597 patients with unstable angina or non-Q wave myocardial infarction participating in the Thrombolysis in Myocardial Infarction (TIMI) 11A substudy, a rapid bedside assay and simultaneous quantitative serum measurement for troponin T were obtained at enrollment.


RESULTS
The composite end point of the sum of death, nonfatal myocardial infarction or recurrent ischemia through day 14 occurred in 33.6% of patients with a positive assay compared with only 22.5% of patients with a negative assay (p = 0.01). Those patients in whom the rapid assay became positive in < or = 10 min had the highest mortality rate of 4.2% through day 14 compared with 1.1% in those patients who had either a late-appearing positive assay (> 10 min) or a negative assay. The duration of hospital stay in the 116 patients (19%) with a positive rapid assay at enrollment was a median of 5 days compared with only 3 days in the 481 patients (81%) with a negative rapid assay at enrollment (p = 0.002).


CONCLUSIONS
A positive rapid assay for troponin T at presentation identifies those patients at risk for higher rates of adverse clinical events and longer, more complicated hospital stays. Stratification of patients by time to development of a positive rapid assay identifies those patients at highest mortality risk.
Antman
E M
EM
Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts 02115, USA. eantman@bustoff.bwh.harvard.edu
Sacks
D B
DB
Rifai
N
N
McCabe
C H
CH
Cannon
C P
CP
Braunwald
E
E
D000368:Aged; D000789:Angina, Unstable / Q000097:blood* / Q000188:drug therapy; D015415:Biomarkers / Q000097:blood; D002423:Cause of Death; D017984:Enoxaparin / Q000008:administration & dosage / Q000627:therapeutic use; D005260:Female; D005343:Fibrinolytic Agents / Q000008:administration & dosage / Q000627:therapeutic use; D005500:Follow-Up Studies; D005544:Forecasting; D006760:Hospitalization; D006801:Humans; D007902:Length of Stay; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000097:blood* / Q000188:drug therapy; D017202:Myocardial Ischemia / Q000097:blood / Q000209:etiology; D019095:Point-of-Care Systems; D011379:Prognosis; D012008:Recurrence; D012307:Risk Factors; D015996:Survival Rate; D013577:Syndrome; D015912:Thrombolytic Therapy; D013997:Time Factors; D014336:Troponin / Q000097:blood*; D020107:Troponin T
D015415:Biomarkers; D017984:Enoxaparin; D005343:Fibrinolytic Agents; D014336:Troponin; D020107:Troponin T